The alfalfa weevil, Hypera postica (Gyllenhal), and potato leafhopper, Empoasca fabae (Harris), are annual, often severe pests of alfalfa, Medicago sativa L., in Missouri. Early harvest of the alfalfa is used by many producers to reduce pest insect numbers. This action results in the reduction or elimination of insecticide use and the conservation of beneficial insects. Two of the most common harvest strategies employed for insect control are mechanical harvest and forage removal by grazing with livestock, usually cattle. In this study, pest and beneficial insect populations were estimated prior to and after each of four harvests of alfalfa annually. Treatments included all harvests by mechanical means, all harvests by grazing with cattle, and two treatments with mixed harvest methods regimes. Data indicate that larval numbers of alfalfa weevil were reduced by approximately 99% for both mechanical and graze methods of harvest. Potato leafhopper adults were reduced by 86% by mechanical harvest as compared to 67% in grazed plots. Similarly, numbers of potato leafhopper nymphs were reduced by 83% and 18% for mechanical and grazed harvest, respectively. A complex of 10 beneficial insect species were grouped for statistical analysis. Numbers of insects in this complex were reduced by an average of 81% in plots harvested mechanically as compared to 64% in grazed plots.